title: MR-arthrography in superior instability of the shoulder: correlation with arthroscopy.
abstract: OBJECTIVE
  This study was undertaken to evaluate magnetic resonance (MR) arthrography in the detection and classification of lesions that may cause superior instability.
  
  
  METHODS
  Forty-two consecutive patients with clinical signs of chronic superior instability of the shoulder underwent MR arthrography followed by arthroscopic surgery. For each patient we retrospectively reviewed the MR arthrography and surgical findings.
  
  
  RESULTS
  We detected 31 superior labral anterior posterior (SLAP) lesions, all confirmed on arthroscopy with three cases of underestimation: in the detection of SLAP lesions, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of MR arthrography were 100%; in the evaluation of the type of SLAP lesion, sensitivity was 100%, specificity was 78.5%, accuracy was 92.8%, PPV was 71.7% and NPV was 100%. All cases of capsular laxity (13/42) and biceps tendon lesions (3/42) were confirmed on arthroscopy with sensitivity, specificity, accuracy, PPV and NPV of 100%. Eleven cuff lesions were detected on MR arthrography, 10 of which confirmed at arthroscopy: sensitivity was 100%, specificity was 96.8%, accuracy was 97.6%, PPV was 90.9% and NPV was 100%. Associated lesions were found in 38/42 patients.
  
  
  CONCLUSIONS
  Superior instability is frequently associated with different anatomical variants or pathological conditions, such as SLAP lesions. The role of MR arthrography is to describe the key features of lesions affecting the superior portion of the shoulder, including location, morphology, extent, and associated injuries and leanatomical variants and to correlate these features with clinical symptoms.
authors.affiliation: Department of Radiology, Insubria University, Via Guicciardini, 21100, Varese, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Genovese
authors.forename: Emanuela
authors.initials: E
authors.lastname: Spanò
authors.forename: Alessandro
authors.initials: A
authors.lastname: Castagna
authors.forename: Anna
authors.initials: A
authors.lastname: Leonardi
authors.forename: Maria Gloria
authors.initials: MG
authors.lastname: Angeretti
authors.forename: Leonardo
authors.initials: L
authors.lastname: Callegari
authors.forename: Carlo
authors.initials: C
authors.lastname: Fugazzola
mesh_terms: D000328:Adult; D001182:Arthroscopy; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000503:physiopathology*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA